Machine for cutting ties in venetian blinds tapes having paired straps



Jan. 24, 1956 E. scHlLKE MACHINE FOR CUTTING TIES IN VENETIAN BLINDS TAPES HAVING PAIRED STRAPS Filed April 5, 1955 ffff JNVENTOR.

fan/A Aw .SCH/KE MACHNE FR CUTTING HES 1N VENETIAN ELNDS TAPES HAVING PARED STRAPS Edward Schilke, Middletown, Conn. application April s, 195s, sei-rn No. 499,449

s Claims. (ci. zemiin) r1`his invention relates to improvements in a machine of the type shown in my U. S. Patent No. 2,242,091, issued May 13, 1941.

As fully set forth in that patent, the machine is specically adapted to cut the ties between the webs in Venetian blind tapes so that only the Slat-supporting straps will extend between the webs.

As is well known, the supporting tape for a Venetian blind comprises two woven webs which extend vertically along the front and back, respectively, of the blind. The front and back webs are connected together by generally horizontal straps which extend between the webs adjacent their corresponding longitudinal edges. The blind slats rest upon the straps. in what is sometimes referred to as a single strap or single ladder tape, the straps are staggered along the opposite longitudinal edges of the webs and one slat will rest upon a strap adjacent one longitudinal edge of the webs and the next adjacent slat will rest upon a strap adjacent the other longitudinal edge of the webs. In what is sometimes referred to as a double strap or double ladder tape, the straps are arranged in pairs along the longitudinal edges of the webs and all of the slats rest upon two straps in each tape. The term ladder is used in that the front and rear webs appear similar to ladder rails `and the straps appear similar to rungs.

As will be described in more detail hereinafter, the straps are formed by warp threads which are connected to the opposed webs by being woven therein at relatively distantly spaced locations along the webs. The said warp threads are also woven into the respective webs in relatively closely spaced locations, the connecting threads being called ties. In order that the webs can be separated so that the straps will hang horizontally, it is necessary to cut the tie threads.

it is the general object of this invention to provide in a machine which is particularly adapted for cutting the ties in a double strap Venetian blind tape improved means for locating the ties for engagement by the cutting shears.

Other objects and advantages of the invention will become apparent to those skilled in the art from the following description taken in connection with the attached drawing wherein,

Fig. 1 is a plan view of a double strap Venetian blind tape;

Fig. 2 is a side elevational View of the tape showing the ties which are cut to separate the tape webs;

Fig. 3 is a View similar to Fig. 2 showing the webs separated after the ties have been cut;

Fig. 4 is a plan view of my improved machine for cutting the ties of a Venetian blind tape;

Fig. 5 is an enlarged fragmentary plan view of the machine showing the details of the structure for positioning the tape ties for engagement by the shears; and

Fig. 6 is a detail view taken as indicated by the line 6-5 of Fig. 5.

2,731,702 Patented aan. 24, tsss The double ladder Venetian blind tape 10 shown in Figs. l, 2 and 3 comprises a woven fabric top web 12 and a similarly woven bottom fabric web 14 which are connected together by straps 16, 16. The straps 16, 16 are arranged in two rows extending along the longitudinal edges of the superimposed webs 12 and 14. The straps 16, 16 comprise warp threads which are not united by weft or filling threads but which are woven into the webs 12 and 14 at regularly spaced intervals along their longitudinal edges. That is, the straps 16, 16 along one longitudinal edge of the tape 10 are woven in the locations 18, 18 to the top web 12 and are woven in the locations 20, 2G to the bottom web 14. It will be observed that the locations 13 and 20 occur in adjacent pairs and the Warp threads extending therebetween constitute the ties 22, 22 which must be cut to separate the webs 12 and 14. The same arrangement of the woven areas 13 and 2@ and the ties 22, 22 occurs along the other longitudinal edge of the tape 1l), the areas 18, 18 and 2d, Ztl and the ties 22, 22 being opposite each other in the double strap tape shown. When the webs are separated as shown in Fig. 3 after the ties 22, 22 have been cut, the straps 16, 16 support the slats of a Venetian blind when the webs 12 and 14 extend vertically, one such web being on the front of the blind and the other on the rear of the blind. Each Venetian blind slat will be supported by a pair of straps in the tape 10.

My improved machine for cutting the ties in the Venetian blind tape is indicated generally by the reference numeral 25 in Fig. 4. The machine is not shown in its entirety, my Patent No. 2,242,091 being reiied upon for a complete disclosure thereof. The description of the aforesaid patent is incorporated herein by reference. The machine elements not shown are not important to an understanding of the present invention, such elements comprising for the most part the machine drive mechanism.

As shown in the drawing, the machine 2S has a fiat table or bed provided by a pair of horizontal plates 26, 26 which are arranged in side-by-side relationship with their inner edges separated, the said plates being supported on legs 27, 27. in the longitudinally extending space between the plates 26, 2d, the tape is supported so that the ties 22, 22 can be cut. The principal tape supporting structure is in the left-hand portion of the machine as viewed in Fig. and the improvements of this invention relate to said tape supporting structure.

The tape is advanced from left to right across the machine bed by means of a reciprocating slide indicated generally by reference numeral 2%, the said slide pivotally supporting a tape-engaging lever 29 at the point 39. The lever 29 is located on the slide 23 adjacent one longitudinal edge of the tape 1@ and has a hooi: 31 which will engage behind a strap 16 to pull the tape along the machine table as the slide is moved toward the right. The lever 29 is spring biased to the strapengaging position shown but is moved out of strapengaging position by a pivoted cam 32 when a roller 33 on the free end of the lever 29 engages the said cam. That is, when the slide 2S is moved toward the left, the roller 33 will engage the cam 32 to pivot the lever 29 counterclockwise. Then, when the roller 33 escapes the cam 32 during left-hand movement, it will be biased back into engagement with a tape strap. When the slide is moved toward the right, the roller 33 will engage the cam 32, but the cam will pivot clockwise and not cause movement of the lever 29. After the roller 33 has positioned the cam during right-hand movement of the slide, the cam will be biased back to the position shown, further counterclockwise rotation of the cam being prevented.

Accordingly, in right-hand` movement of the slide 28, the tape l will be moved toward the right, but in lefthand movement of the slide 28, there will be no tape movement effected and the tape-engaging hook 31 will be moved along the tape for re-engagement with another strap 16.

The machine drive means (not shown) which reciprocates the slide 23 also pivots a tape-retaining arm 34 into and out of engagement with the tape. When the slide 2S is moved toward the left, the arm 34 engages the top of the tape 1t) and holds it in advanced position. When the movement of the slide 2S is toward the right, the arm 34 is elevated out of engagement ywith the tape so that it can be freely advanced along the machine.

In each step-by-step advance of the tape from left to right, successive ties 22, 22 along the opposite longitudinal edges of the tape i0 are positioned for engagement by two pairs of shears 35, which are respectively l0- cated on opposite sides of the tape, one pair of shears, namely the lower pair, being slightly to the left of the other pair. Accordingy, in each step-by-step position of the tape if), a tie 22 in the traps along one longitudinal edge will be positioned for cutting by its associated shears while a tie 22 on the other longitudinal edge will be positioned for cutting by its associated shears 35.

The slide 2f provides the actuating means for moving the shears 35, 35 into and out of engagement with the ties at opposite longitudinal edges of the tape. Each pair of shears has associated operating mechanism identical to the other pair, similar elements of the operating mechanism being identified by the same reference numerals. More specically, the shears operating mechanism comprises a lever 37 which is pivoted to the machine table at 38 and which at one end supports a cam following roller 39. The roller is engageable by a cam block 40 carried by the slide 23, there being one such block 40 on each side of the slide. The lever 37 is biased to normally retract its associated shears from the tape 10 but when the respective block di) engages the roller 39, the lever 37 is pivoted to insert vits respective shears between the webs 12 and 14.

After the shears have been inserted between the webs they are closed by mechanism which in each case comprises a lever il pivoted at 42 to the machine bed and carrying a shear closing plate 43 on one end thereof. At the other end of the lever 41 a roller 44 is located for engagement by the respective cam block iii so that the said lever will he pivoted to move the closing plate 43 towards the respective shears 35. The levers 41, 41 are biased normally to move the plates 43, 43 away from the shears 35, 35. In moving toward the shears, the plates 43, 43 engage screws 45, 45 which are adjustably secured to the scissors arms of each pair of shears and in such movement of the plates 43, 43, the shears will be closed.

It is important to observe that in movement of the slide 28 toward the left, the shears retracting lever will be engaged first to insert the shears between the webs and then the shears closing lever will be engaged to eect closing of the shears.

Spring biased arms d6, 45 are pivotally mounted on the machine bed on opposite sides of the tape 10, there being one such arm adjacent each pair of shears. The arms are biased to normally be engaged between the webs of the tape with a strap i6. lt is the purpose of the arms to separate the webs and appiy some tension to the tape 10 so that the ties .'22, 22 can conveniently be engaged by the shears and then cut.

In addition to the pivoted arms 46, 46 there is provided in accordance with the present invention, tape supporting means adapted to assure properpositioning of the ties for engagement by the shears. The said means, comprise a pair of spring leaves 47 and 48 which are supported in superimposed cantilever fashion between the plates 26, 26 from the left-hand side of the machine bed. The upper leaf 47 has two fingers, namely a finger 49 and a linger 50 which engage the tape under the rows of straps and ties on the opposite longitudinal edges of the tape. The spring leaves are so arranged that they will exert upward pressure on the tape, thus applying some tension thereto against the force applied by the tape retaining arm 34. The tape 10 is drawn across the spring leaves 47 and 48 over a plate 51 and a Weighted plate 52 is detachably supported on the plate 51 so that its weight wiil bear against the tape, thus applying additional tension thereto.

In addition to the foregoing, a pair of rollers 53, 53 are supported with their common axis transversely of the tape on an arm 54 which extends from the plate 2. The rollers also apply tension to the tape and some pressure downwardly in opposition to the pressure afforded by the spring leaves 47 and 4S. A third roller 55 is supported on a shaft 56 which is pivoted to a block 57 on the machine table so that the roller 55 can be brought into engagement with the tape 10 on that portion thereof which is adjacent the uppermost shear as viewed in the drawing.

It has been found that with the tape tensioning means provided in accordance with the present invention the ties 22, 22 are precisely located for engagement by the shears 35, 3S during each step in the advance of the tape 10. Without the tape tensioning means shown, or its equivalent, there is the possibility of not properly positioning the ties due to backlash and inertia forces when the tape is advanced by the recprocating slide.

It will readily be understood that modifications may be made within the scope of the inventionand that it is not the intent to define or limit the invention in the description. The claims forming a part of this specification are relied upon as properly reflecting the spirit and scope of the invention.

l claim asmy invention:

l. In a machine for cutting the ties in a Venetian blind tape comprising a pair of elongated superimposed webs which are connected by threads along both longitudinal edges and which threads form the ties and Slat-supporting straps of the tape and wherein the machine includes a table, a slide reciprocable along the table and having means engageable with the tape to advance the same from one end of the table toward the other end thereof during movement of the slide in one direction, means engageable with the tape to hold the same while the slide moves in the oppoiste direction, and cutting means operatively associated with said slide and constructed andV arranged to be inserted between the webs from the longitudinal edges thereof to cut a tie adjacent each longitudinal edge during movement of the slide in said opposite direction, the improvement comprising at least one leaf spring supported adjacent said one end of the table to apply spring force upwardly against the tape, and means holding the tape in firm engagement with the leaf spring, the spring force being applied to tension the tape so that a tie along each longitudinal edge of the tape will be properly positioned for engagement by the cutting means.

2. In a machine for cutting the ties in a Venetian blind tape comprising a pair of elongated superimposed webs which are connected by threads along both longitudinal edges and which threads form the ties and Slat-supporting straps of the tape and wherein the ymachine includes a table, a slide reciproeable along the table and having means engageable with the tapeto advance the samefrom one end of the table toward the other end thereof during movement of the slide in one direction, means engageable with the tape to hold the same while the slide moves in the opposite direction, and cutting means operatively associated with said slide and constructed and arranged to be inserted between the webs from the longitudinal edges thereof to cut a tie adjacent each longitudinal edge during movement ofthe sliders-in said opposite-direction, the improvement comprising at least one leaf spring supported on the table adjacent said one end thereof and arranged to apply spring force upwardly against the tape, and a weighted plate detachably supported on said one end of the table to bring its weight to bear on top of the tape, the spring force and weighted plate being applied to tension the tape so that a tie along each longitudinal edge of the tape will be properly positioned for engagement by the cutting means.

3. In a machine for cutting the ties in a Venetian blind tape comprising a pair of elongated superimposed webs which are connected by threads along both longitudinal edges and which threads form the ties and Slat-supporting straps of the tape and wherein the machine includes a table, a slide reciprocable along the table and having means engageable with the tape to advance the same from one end of the table toward the other end thereof during movement of the slide in one direction, means engageable with the tape to hold the same while the slide moves in the opposite direction, and cutting means oper atively associated with said slide and constructed and arranged to be inserted between the webs from the longitudinal edges thereof to cut a tie adjacent each longitudinal edge during movement of the slide in said opposite direction, the improvement comprising at least one leaf spring supported on the table adjacent said one end thereof and arranged to apply spring force upwardly against the tape, a weighted plate detachably supported on said one end of the table to bring its weight to bear on top of the tape, and at least two rollers supported on axes extending transversely of the tape, the rollers being in engagement with the top of the tape adjacent the opposite longitudinal edges thereof, respectively, the spring force, weighted plate and rollers being applied to the tape to tension the same so that a tie along each longitudinal edge of the tape will be properly positioned for engagement by the cutting means.

4. In a machine for cutting the ties in a Venetian blind tape comprising a pair of elongated superimposed webs which are connected by threads along both longitudinal edges and which threads form the ties and Slat-supporting straps of the tape and wherein the machine includes a table, a slide reciprocable along the table and having means engageable with the tape to advance the same from one end of the table toward the other end thereof during movement of the slide in one direction, means engageable with the tape to hold the same while the slide moves in the opposite direction, and cutting means operatively associated with said slide and constructed and arranged to be inserted between the webs from the longitudinal edges thereof to cut a tie adjacent each longitudinal edge during movement of the slide in said opposite direction, the improvement comprising at least one leaf spring supported on the table adjacent said one end thereof and having a plurality of extending fingers which are respectively arranged to apply spring force upwardly against the longitudinal edge portions of the tape, and a weighted plate detachably supported on the said one end of the table to bring its weight to bear on top of the tape, the spring force and weighted plate being applied to tension the tape so that a tie along each longitudinal edge of the tape will be properly positioned for engagement by the cutting means.

5. In a machine for cutting the ties in a Venetian blind tape comprising a pair of elongated superimposed webs which are connected by threads along both longitudinal edges and which threads form the ties and Slat-supporting straps of the tape and wherein the machine includes a table, a slide reciprocable along the table and having means engageable with the tape to advance the same from one end of the table toward the other end thereof during movement of the slide in one direction, means engageable with the tape to hold the same while the slide moves in the opposite direction, and cutting means operatively associated with said slide and constructed and arranged to be inserted between the webs from the longitudinal edges thereof to cut a tie adjacent each longitudinal edge during movement of the slide in said opposite direction, the improvement comprising at least one leaf spring supported on the table adjacent said one end thereof and having a plurality of extending lingers which are respectively arranged to apply spring force upwardly against the longitudinal edge portions of the tape, a weighted plate detachably supported on said one end of the table to bring its weight to bear on the top of the tape, and at least two rollers supported on axes extending transversely of the tape, the rollers being in engagement with the top of the tape over the said spring fingers, the spring force, weighted plate and rollers being applied to the tape to tension the same so that a tie along each longitudinal edge of the tape will be properly positioned for engagement by the cutting means.

References Cited in the le of this patent UNITED STATES PATENTS 2,242,091 Schilke May 13, 1941 

